Graphics are weird

[miguelneto]

Since I've bought the game (5 days ago) I see in the game the walls are purple when I get close or if there is any light nearby it. The objects and items get also wierd colours varying from blue to green and a mix of it. It gets worse when I get close. Also the game isn't dark at all even if there is no light and I can't see the light from the flashlight or glowing stick.

My videocard is AMD Radeon 1Gb and my windows is 7. I have already updated my videocard.

Can you help me?
Thank you